18027-46-8

Upstream product

• 998-30-1 Triethoxysilane 
• 108-94-1 cyclohexanone 
• 10026-04-7 tetrachlorosilane 
• 78-10-4 tetraethoxy orthosilicate 
• 108-93-0 cyclohexanol 

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• 108-93-0 cyclohexanol 

Relevant academic research and scientific papers

Reduction of Carbonyl Compounds with Hydrosilanes on Solid Acid and Solid Bases

Hydrosilylations of carbonyl compounds were performed on the surfaces of solid acids and bases.Strongly acidic clays efficiently catalyzed the reduction of aldehydes and ketones with trialkylsilanes (e.g.Et3SiH) to afford symmetrical ethers or hydrocarbons, depending upon the characters of substituents around carbonyl groups.Reduction-resistant ketone like 4,4'-dimethoxybenzophenone was found to be reduced with Et3SiH under the catalytic influence of the highly acidic clay.In contrast, trialkoxysilanes (e.g. (EtO)3SiH) became labile in contact with solid base like hydroxyapatite, reducing a variety of carbonyl compounds to yield alkoxy(triethoxy)silane in good yields.It was revealed that besides fluoride salts, solid bases bearing mild basicity and relatively large surface areas can activate the trialkoxysilane enough for reduction of carbonyl functions.

RHODIUM(II) COMPLEXES AS HYDROSILYLATION AND HYDROGENATION CATALYSTS

Two phosphine-rhodium(II) complexes, bis(tris-o-tolylphosphine)dichlororhodium(II) and bis(tricyclohexylphosphine)dichlororhodium(II), have been found to be active catalysts for the hydrosilylation of a variety of organic substrates, and, in conjunction with triethylaluminum, to be hydrogenation catalysts.

Synthesis of silyl iron hydride: Via Si-H activation and its dual catalytic application in the hydrosilylation of carbonyl compounds and dehydration of benzamides

The hydrido silyl iron complex (o-Ph2PC6H4SiMe2)Fe(PMe3)3H (2) was obtained via the activation of the Si-H bond of the bidentate silyl ligand o-Ph2P(C6H4)SiMe2H (1) by Fe(PMe3)4. 2 showed good to excellent catalytic activity in both the reduction of aldehydes/ketones and the dehydration of benzamide. In addition, with complex 2 as a catalyst, α,β-unsaturated carbonyls could be selectively reduced to the corresponding α,β-unsaturated alcohols. The mechanisms of the formation of 2 and the catalytic dehydration process are proposed and partly experimentally verified.

Preparation of hydrido [CNC]-pincer cobalt complexes via selective C-H/C-F bond activation and their catalytic performances

Polyfluorinated aryl imines 2,4,5-R1,R2,R3-C6H2-HC═N-1-C10H7 (R1 = F, R2 = F, R3 = H (1); R1 = F, R2 = H, R3 = F (2) and R1 = F, R2 = F, R3 = F (3)) and F5C6-HC═N-1-C10H7 (7) reacted with CoMe(PMe3)4 to give rise to hydrido [CNC]-pincer cobalt(iii) complexes (2,4,5-R1,R2,R3-C6H-HC═N-1-C10H6)Co(H)(PMe3)2 (R1 = F, R2 = F, R3 = H (4); R1 = F, R2 = H, R3 = F (5); R1 = F, R2 = F, R3 = F (6)) and (F4C6-HC═N-1-C10H6)Co(H)(PMe3)2 (8) via selective C-F/C-H bond activation. Penta-coordinate dicarbonyl cobalt(i) complexes (2,4,5-R1,R2,R3-C6H-HC═N-1-C10H7)Co(CO)2(PMe3) (R1 = F, R2 = H, R3 = F (9); R1 = F, R2 = F, R3 = F (10)) were obtained from reactions of hexa-coordinate cobalt(iii) complexes 5 and 6 with carbon monoxide through reductive elimination. Cobalt(iii) halides (2,4,5-R1,R2,R3-C6H-HC═N-1-C10H6)Co(i)(PMe3)2 (R1 = F, R2 = F, R3 = H (11); R1 = F, R2 = H, R3 = F (12); R1 = F, R2 = F, R3 = F (13)) and (2,4,5-R1,R2,R3-C6H-HC═N-1-C10H6)Co(Br)(PMe3)2 (R1 = F, R2 = F, R3 = H (14); R1 = F, R2 = H, R3 = F (15); R1 = F, R2 = F, R3 = F (16)) were prepared by the interaction between hydrido cobalt(iii) complexes 4-6 and MeI or EtBr. The molecular configurations of complexes 4, 8, and 11 were determined by single crystal X-ray diffraction. We then confirmed that the four hydrido cobalt(iii) complexes 4-6 and 8 could be used as catalysts for reduction of aldehydes and ketones. Complex 8 is the best catalyst among the four complexes and can selectively catalyze the carbonyl groups of α,β-unsaturated aldehydes and ketones.

Synthesis, characterization and reactivity of iron- and cobalt-pincer complexes

The tBuPONOP (2,6-bis(di-tert-butyl-phosphinito)pyridine) complexes of iron and cobalt, (tBuPONOP)FeCl2 (1) and (tBuPONOP)CoCl2 (2)) have been prepared. Both complexes are paramagnetic and the solid-state structures of 1 and 2 were determined by single crystal X-ray diffraction studies. Analogous Fe and Co complexes of the tBuPNP (2,6-bis(di-tert-butyl-phosphinomethyl)pyridine) ligand (3 and 4, respectively) were prepared to allow comparison between the closely related pincer ligands in the hydrosilylation of carbonyl moieties. All four complexes were found to be catalytically active when treated with NaBEt3H, which was assumed to generate a metal-hydride species in-situ.

Synthesis of [POCOP]-pincer iron and cobalt complexes via Csp3-H activation and catalytic application of iron hydride in hydrosilylation reactions

Csp3-H bond activation in diphosphinito pincer ligand (Ph2PO(o-C6H2-(4,6-tBu2)))2CH2 (1) (POCH2OP) was achieved by Fe(PMe3)4 and CoMe(PMe3)4 to afford complexes (POCHOP)Fe(H) (PMe3)2 (2) and (POCHOP)Co(PMe3)2 (4) under mild conditions. Hydrido iron complex 2 reacted with iodomethane via the elimination of methane to deliver complex (POCHOP)FeI(PMe3) (3). The ligand replacement in Ni(PMe3)4 by 1 gave rise to nickel(0) complex (POCH2OP)Ni(PMe3)2 (5) without Csp3-H bond activation of the pincer ligand (1). It was confirmed that the hydrosilylation of aldehydes and ketones could be effectively catalyzed by hydrido iron complex 2. Complexes 2-5 were characterized by spectroscopic methods and X-ray single crystal diffraction analysis. This journal is

Synthesis of iron hydrides by selective C-F/C-H bond activation in fluoroarylimines and their applications in catalytic reduction reactions

The reactions of Fe(PMe3)4 with different 2,6-diflurophenylarylimines 1-5 were explored. Fluoroarylimines 1-3, the aryl rings of which are substituted with electron-withdrawing groups, reacted with Fe(PMe3)4 to afford the C-H activation products 6-8. However, if the aryl rings of the fluoroarylimines were substituted with electron-donating groups, the iron hydrides 9 and 10 were obtained from the reactions of the fluoroarylimines with Fe(PMe3)4 through C-F bond activation. In a further study, silanes, especially triethoxysilane, were found to benefit the reactions and improve the yields of the hydridoiron complexes. The three-component reaction of Fe(PMe3)4, a fluoroarylimine, and a silane could also be utilized in reactions involving 2,6-(CH3)2C6H3-C(=NH)-2,6-F2C6H3 (13) and 2,6-F2C6H3-C(=NH)-C6F5 (16) to synthesize iron hydrides (15 and 18). The hydridoiron complexes could be utilized as efficient catalysts in the hydrosilylation of aldehydes and ketones. Furthermore, cinnamaldehydes were selectively reduced to the corresponding cinnamyl alcohols in high yields. The mechanism of the catalytic reduction reaction was studied extensively through operando IR spectroscopy.

A highly active manganese precatalyst for the hydrosilylation of ketones and esters

The reduction of (Ph2 PPrPDI)MnCl2 allowed the preparation of the formally zerovalent complex, (Ph2 PPrPDI)Mn, which features a pentadentate bis(imino)pyridine chelate. This complex is a highly active precatalyst for the hydrosilylation of ketones, exhibiting TOFs of up to 76,800 h-1 in the absence of solvent. Loadings as low as 0.01 mol % were employed, and (Ph2 PPrPDI)Mn was found to mediate the atom-efficient utilization of Si-H bonds to form quaternary silane products. (Ph2PPrPDI)Mn was also shown to catalyze the dihydrosilylation of esters following cleavage of the substrate acyl C-O bond. Electronic structure investigation of (Ph 2PPrPDI)Mn revealed that this complex possesses an unpaired electron on the metal center, rendering it likely that catalysis takes place following electron transfer to the incoming carbonyl substituent.

Iron hydride complexes bearing phosphinite-based pincer ligands: Synthesis, reactivity, and catalytic application in hydrosilylation reactions

Treatment of resorcinol-derived bis(phosphinite) ligands 1,3-(R 2PO)2C6H4 (R = iPr and Ph) with Fe(PMe3)4 furnishes iron POCOP-pincer hydride complexes [2,6-(R2PO)2C6H3]Fe(H) (PMe3)2 (R = iPr, 1a; R = Ph, 1b) with two PMe3cis to each other. The isopropyl complex 1a undergoes ligand substitution upon mixing with CO to give [2,6-(iPr 2PO)2C6H3]Fe(H)(PMe 3)(CO). The kinetic product (2a) of this process contains a CO ligand trans to the hydride, whereas the thermodynamic product (2a′) has a CO ligand cis to the hydride. The displacement of PMe3 in 2a by CO takes place at an elevated temperature, resulting in the formation of [2,6-( iPr2PO)2C6H3]Fe(H)(CO) 2 (3a). These new iron POCOP-pincer hydride complexes catalyze the hydrosilylation of aldehydes and ketones with different functional groups, and 1a is the most efficient catalyst for this process. Isotopic labeling experiments rule out the hydride ligand being directly involved in the reduction. The hydrosilylation reactions are more likely to proceed via the activation of silanes or carbonyl substrates after ligand (PMe3, or CO in the case of 3a) dissociation from the iron center.

HYDROSILYLATION OF CARBONYL COMPOUNDS CATALYZED BY SOLID ACIDS AND BASES

Hydrosilylation of carbonyl compounds with hydrosilane is efficiently catalyzed by inorganic solid acids and bases such as Fe(3+) ion-exchanged montmorillonite and hydroxyapatite (Ca10(PO4)6(OH)2) at reaction temperatures between 25 and 90 deg C.Enones ar